Shock unit



J. H. STEDMAN SHOCK UNIT Original Filed April 30, 1925 Patented Aug. 10,1926.

UNITED STATES PATENT OFFICE.

SHOCK UNIT.

Continuation of application Serial No. 26,866, filed April 30, 1925.

Serial No. 62,609.

This invention relates to the manufacture of shock units, and moreparticularly to that type of shock unit adapted for mounting on the legsof any kind of bed frames, although other uses will be ascertained fromthe following description.

Such articles of this nature as I am aware of, variously called bumpers,buffers, wall-protectors and the like, ha e the fatal commercialdisadvantage of some mechanical construction, oftentimes some- Whatcomplicated, through which the article is secured to the piece offurniture. The suggestions heretofore proposed ignore the two mainessentials of a successful shock unit, namely, extreme simplicityenabling expeditious application and removal by unskilled labor, and aformation that affords the minimum opportunity for collection of dust.The provision of a surface that not only offers little opportunity forholding dust but also is easily and quickly cleaned of dust isadvantageous in all cases but is highly important where these shockunits are used on hospital beds. Hospital beds, because often moved fromone place to an other within the hospital, particularly requireprotectors against marring the woodwork of walls and doorways, and suchdevices olfering dust and dirt collecting crevices would not beacceptable to the hospital authorities.

The object of the present invention is to provide a shock unit for thepurpose described having all of the advantages just referred to.

To the accomplishment of this object the invention comprises the novelcharacteristic features hereinafter described and then pointed out intheir true scope in the appended claims. The nature and uses of theinvention will readily be understood from a description of the bestforms of the shock unit at present known to me, illustrated in theaccompanying drawings, in which:

Figure 1 is a view, in perspective, of the preferred commercial form ofthe shock unit;

Fig. 2 is a view, in perspective, of a slightly modified form of theshock unit;

Fig. 3 illustrates a hospital type metallic bed having plain tubularlegs and showing a shock unit like either Fig. 1 or Fig. 2 appliedthereto;

Fig. 4 is a view, in plan, of a further modification, adapted to anyform of the This application filed. October 15,

shock unit, providing for expeditious mounting on the legs of householdtype metallic beds that have a finish head or moulding at the lower end;and

Fig. 5 is a View, in elevation. of the lower end of the leg of ahousehcld bed with the modified type of shock unit shown in Fig. &applied thereto.

In all the embodiments of the invention illustrated in the drawing theshock unit is formed by moulding rubber in a manner to produce a body 5of generally oblate spheroidal form having a substantially semi-circularperipheral edge-surface 6 and a central opening '7 proportioned to fitthe leg of the bed or other household article on which the unit is to beused, this opening being provided at its edge, preferably at each end,with an outwardly projecting rim or binding lip 8. The lip 8 forms ahighly important feature of the unit in that the slight shrinkage thatoccurs when the rubber cools, causes the opening 7 to contract slightlytoward its ends and enables the lip or lips to obtain a frictional gripon the leg of the bed, or other article, when said leg lies within thecentral opening. Hospital beds are designed to prevent the collection ofdust, as far as possible, the legs ordinarily being of pipe form with nofinish foot, such as a bead or moulding. Such a bed leg is illustratedat 9 (Fig. 3) and, on removing the castor, the shock unit may readily beforced on it by endwise pressure. The binding lip 8 is moulded to arelatively thin edge as shown in Figs. 1 and 2, and a fillet is providedbetween this edge and the bodv 5.

In Fig. 2 the mould is so formed that the lip 8 is provided withsubstantially a knife edge 10 designed to merge into the surface of thebed leg when applied thereto. Ow ing to manufacturing difficulties it isnot always possible to produce an unbroken edge on the lip as thin asthat illustrated by Fig. 2. WVhile the shock unit may be perfect whenremoved from the mould the na ture of the material is such that it maycrack at the ends of the opening .7 and even break away along the freeedge under the strains imposed when placed in use. This, while notdetracting from the value of the unit as a buffer or bumper, gives it anun' sightly appearance that is undesirable. To overcome this the thinedges 10 may be trimmed slightly after the unit is removed from themould, but the better practice is to provide a lip that will be strongenough to successfully resist the strains under which the unit is placedwhen in use or from careless handling. The lip configuration shown at 8(Fig. 1) has been selected, after experimentation, as providing therequisite strength and minimum dust collecting surface, but thoseskilled in the art will recognize that the lip 8 may have otherconfigurations with an equivalent re sult, without departing from thespirit and scope of the invention. Thus a minimum of dust collectingsurface is presented at the joinder of the shock unit with the articlethat supports it and its surface characteristics are such that all partsof the unit may easily be kept clean by merely wiping the surface.

Household beds of metal usually have their legs terminate in a finishfoot in the form of a bead or more elaborate moulding 11 (see Fig. 5)that prevents the shock unit from being slipped on the bed leg byendwise pressure. To permit seating the type of unit just described onbed legs 12 of this character, the body 5 is sliced preferably, but notnecessarily, radially as at 13 (Fig. 5) from the edge 6 through the wallof the central opening 7. The meet ing faces 14 (Fig. 4c) of the slice13 may be drawn apart sufficiently to permit a bed leg 12, above itsmoulding 11, to be passed between them and thus into the opening 7 It isproposed to manufacture the unit of such a high quality of rubber thatafter this operation the meeting faces 14 will naturally close togetherimmediately. Ordinarily this spring of the material will hold the unitfirmly in place on the bed leg when aided, as heretofore explained, bythe frictional hold of the binding lip or lips 8. To guard against anypossibility of accidental displacement of the unit from the bed leg themeeting faces let may be coated with a quick-curing vulcanizing cementand then held pressed together for a short time by winding adhesive tapeabout the surface 6. After the cement has acted to cause the meetingfaces is to adhere to each other the tape is removed and the unitremains permanently in place.

It is within the scope of the invention to provide one instead of twobinding lips 8 and it is obvious that the shape of the body 5 may bechanged at will. The opening 7 will be made of several differentdimensions as may be necessary to fit the various standard types of bedand furniture legs, or of any other required dimensions.

I believe that I am the first to produce a rubber shock unit of simpleform that provides a buffer body having an adequate bumping surface andis held in place on the furniture leg by reason of its own integralconstruction.

The fundamental features of the present invention were described andclaimed in an application for improvements in shock units filed by meApril 30, 1925, Serial No. 26,866, aifid this application is acontinuation there- 0'.

The nature and scope of the invention having been indicated, and thepreferred embodiments thereof having been specifically described, whatis claimed as new, is

1. A shock unit for furniture legs comprising a disk-like body of rubberhaving a central opening for receiving said leg, each end of saidopening being provided with a peripheral lip connected to said body by afillet and tapering outwardly to a relatively thin edge.

2. A shock unit for furniture legs comprising a disk-like body of rubberhaving a central opening provided with a relatively thin rubber lip atits edge, said body being sliced apart from its outer edge through thewall of said central opening and lip.

3. A shock unit for furniture legs comprising a rubber body of generallyoblate spheroidal form, having a central opening for receiving said leg,the wall of said opening being lengthened by the provision of anintegral peripheral rubber lip having a relatively thin outer edge butincreasing in thickness from said edge to its base where it joins theface of the body.

JAMES HERBERT STEDMAN.

